RAM Mounts Vibe Safe with NPT Adapter for 2-Hole Phone Holders Say goodbye to vibrations with the RAM Mounts Vibe Safe vibration damping adapter designed for 2-hole phone holders. Features: RAM Vibe-Safe dampens a wide range of vibration frequencies NPT thread connection allows for rotation between portrait and landscape while remaining secure Compatible with RAM holders with 2-Hole Amps hole pattern, and the metal diamond ball adapter (Ram-B-238U) for any B size ball and socket mount Unique structure and thoughtfully designed with all industries in mind